Move bind mount handling into a separate file.
    
    2011-03-30  Miloslav Trmač  <mitr@redhat.com>
    
    	* src/bind-mount.c (bind_mount_paths, bind_mount_paths_index)
    	(last_path_mounted_mtime, bind_mount_paths_obstack)
    	(bind_mount_paths_mark, rebuild_bind_mount_paths, is_bind_mount): Move
    	from ...
    	* src/updatedb.c: ... here.
    	* src/bind-mount.c (bind_mount_init): Rename and move from ...
    	* src/updatedb.c (init_bind_mount_paths): ... here, and move
    	conf_prune_bind_mounts handling to the caller.
    	* src/bind-mount.h: New file.
    	* Makefile.am (src_updatedb_SOURCES): Add src/bind-mount.c and
    	src/bind-mount.h.
    
    	* src/lib.c (string_list_contains_dir_path): Rename and move from...
    	* src/updatedb.c (path_is_in-list): ... here.  All callers updated.
    	* src/lib.h (string_list_contains_dir_path): New declaration.